To conduct indoors a test on a solar cell composed of a plurality of cells according to the prior art, it is necessary to simulate sunlight required for the evaluation of the performance of the solar cell in utilizing sunlight.
Referring to FIG. 1, there is shown a schematic view of a conventional simulated sunlight generating device. The simulated sunlight-based test involves driving a light-emitting diode array 2 to emit a high-brightness light L for functioning as the simulated sunlight. The light-emitting diode array 2 comprises a plurality of light-emitting diodes 22. The light-emitting diodes 22 each emit the light L. The light L emitted from each of the light-emitting diodes 22 travels a distance d before reaching cells 42 of a solar cell 4 to undergo a test. The distance d, however, opens up a possibility that the light L from any one of the light-emitting diodes 22 misses one of the cells 42, or, in other words, the possibility that one of cells 42 does not necessary receive the full illumination intensity of the light L from the light-emitting diodes 22, for reasons below. The light-emitting diodes 22 each emit the light L by a scattering angle θ. If each of the cells 42 is to receive the light L from all the light-emitting diodes 22, each of the cells 42 will have to be present within the range of angle covering all the scattering angles θ. In practice, it is impossible for any one of the cells 42 to fall within the range of angle covering all the scattering angles θ of the light-emitting diodes 22. The above drawbacks of the prior art cannot be overcome by reducing the distance d between the light-emitting diodes 22 and the solar cell 4 or positioning the light-emitting diodes 22 immediately above the cells 42, respectively.
Accordingly, it is imperative to provide a simulated sunlight specific to one and only one cell or even specific to a solar cell in its entirety. To this end, the present invention provides a simulated sunlight generating device that is easy to install and maintain, incurs low costs, and is highly flexible and efficient.